Production of esters of sulphonic acids



Patented Sept. 15, rear was,

HEINRICH BERTSGH, OF CHEMNITZ, GERMANY, ASSIGNOR TO H. TH. BfJ HME .AKTIEN- GESELLSCHAFT, OF CHEMNITZ, GERMANY PRODUCTION OF ESTERS OF SULPHONIC ACIDS No Drawing. Application filed July 16, 1929, Serial No. 378,818, and in Germany July 19, 1923.

The principal object of this invention is to provide a practical and feasible process for the manufacture of the esters of the sulpho- -acids which may be formed by the sulphonation of natural fats, including both glyceride fats, cholestride fats, the corresponding fatty acids and also the esters of the aromatic sulpho-acids which at the same time are cyclic carboxylic acids or carboxylic acids in the side chain. The direct production of the alkyl or aryl esters, particularly the alkyl esters having comparatively few carbon atoms in the alkyl radiele, cannot be carried out in an easy and rational manner on account of concomitant reactions. After or even simultaneously with the sulphonation of fatty acids, the esterification reaction does not proceed at all smoothly but is frequently disturbed by the accompanying reactions the results of which, moreover, are variable and uncontrollable.

According to the present invention the alkyl or aryl esters of sulpho-acids which are also earboxylic acids can be obtained by a smoothly running process by first producing the esters of the carboxylic acids, that is for example of the fatty acids, and then sulphonating these esters. It has proved that in this process not only does sulphonation of the esters take place but also the alkyl or aryl radicle attached to the carboxyl group passes to the sulphoxyl group, so that the end product consists of the esters of the sulpho-fatty acids, possibly in admixture with carboxylic acid esters or esters in which the sulphuric acid radicle is esterified as well as the carboxyl group. In a large number of cases the process itself also presents the advantage of providing an easier mode of working in so far as the fatty' acid esters of the lower alcohols (say for example up to cetyl alcohol) are more liquid or easily liquefied than the natural fats, that is than the glycerides or cholesterides of the corresponding fatty acids, and have a much lower melting point. It is possible therefore to sulphonate many of the esters at low temperatures even without the addition of diluents which may possibly have a disturbing effect; this enables a more complete introduction of sulphuric acid into the molecule.

The following examples will serve to illustrate the process: 5

Example 1 In 360 'kgs. of ricinoleic acid butyl ester, 500 kgs. of 66 B. sulphuric acid are slowly introduced with constant stirring and at a temperature between 5 and 10 C. After all the sulphuric acid has been introduced, the reaction mixture is poured onto ice and is then washed with saturated Glaubers salt solution, the product being shaken up with the salt solution, then allowed to settle whereby two layers form, the acid salt solution being then separated off. By the addition of soda lye the washed reaction productis then neutralized.

The compounds so produced are not onl exceptionally strong wetting agents whic may be used in the textile and leather industries and for the wetting or moistening of metals, powers, colours, dyestuffs and the like but in addition thereto, are also extremely suitable for use as additions to treatment liquids such as are employed, for example, in the etching and corrosion of metals. Furthermore said compounds are strong solution facilitating media and emulsifiers and may therefore also be used for fat cleavage purposes.

Ewample 2 Ewample 3 The procedure described in Example 2 is followed except that 386 kgs. of oleic benzyl ester is treated instead of the ricinoleic benzyl ester.

I claim: 1. The process of producing esters of sulphonic acids which are also carboxylic acids comprising treating a carboxylic acid ester selected from the group consisting of alkyl esters having fewer carbon atoms than cetyl alcohol and aryl esters with a sulphonating compound.

2. The process of producing esters of sulphonic acids which are also carboxylic acids comprising converting a fatty acid into the corresponding carboxylic acid ester, said ester being selected from the group consisting of alkyl esters having fewer carbon atoms than cetyl alcohol and aryl esters, with a sulphonating compound. r V

'3. The process of producing esters of sulphonic acids which are also carboxylic acids comprising converting a fatty acid into the corresponding carboxylic acid ester, said ester being selected from the group consisting of alkyl esters having fewer carbon atoms than cetyl alcohol and aryl esters, and then sulphonating said carboxylic acid ester at a low temperature without the addition of a diluent. v

4. The process of producing esters of sulphonic acids which are also carboxylic acids comprising converting a fatty acid into the corresponding carboxylic acid ester, said ester being selected from the group consisting of alkyl esters having fewer carbon atoms than cetyl alcohol and aryl esters and then sulphonating said carboxylic acid ester at a low temperature and removing the excess sulphuric acid with the aid of Glaubers salt solution.

5. The process of producing esters of sulphonic acids which are also carboxylic acids comprising treating an aryl ester of a carboxylic acid with a sulphonating compound.

6. The process of producing esters of sulphonic acids which are also carboxylic acids comprising treating an alkyl ester, having fewer carbon atoms than the cetyl ester, of a carboxylic acid with a sulphonating agent.

7. The process of producing esters of sulphonic acids which are also carboxylic acids comprising treating a butyl ester of a fatty acid with a sulphonatin compound.

8. The process of pro ucing esters of sulphonic acids which are also carboxylic acids comprising treating the butyl ester of ricinoleic acid with a sulphonating compound.

DR. HEINRICH BERTSCH. 

